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SDL_DisplayFormatAlpha(3)      SDL API Reference     SDL_DisplayFormatAlpha(3)


SDL_DisplayFormatAlpha - Convert a surface to the display format


#include "SDL.h" SDL_Surface *SDL_DisplayFormatAlpha(SDL_Surface *surface);


This function takes a surface and copies it to a new surface of the pixel format and colors of the video framebuffer plus an alpha channel, suitable for fast blitting onto the display surface. It calls SDL_Con- vertSurface If you want to take advantage of hardware colorkey or alpha blit accel- eration, you should set the colorkey and alpha value before calling this function. This function can be used to convert a colourkey to an alpha channel, if the SDL_SRCCOLORKEY flag is set on the surface. The generated sur- face will then be transparent (alpha=0) where the pixels match the colourkey, and opaque (alpha=255) elsewhere.


If the conversion fails or runs out of memory, it returns NULL


SDL_ConvertSurface, SDL_SetAlpha, SDL_SetColorKey, SDL_DisplayFormat, SDL_Surface SDL Tue 11 Sep 2001, 23:01 SDL_DisplayFormatAlpha(3)

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